As hard as it is to wait, try to be patient. Remember, in the worst case, even if you do not get selected to attend NASS, it does NOT mean that you aren't competitive to earn an appointment. Many people who don't go to NASS DO get appointments, and vice versa.
WRT waiting on the actual application, yes, it is VERY hard, even for us parents! Just imagine, instead of waiting from 1 February to now, waiting from July of one year to May of the next! All's well that ends well, and the longer you wait, the sweeter it is when that big blue binder finally does arrive.